Netext Working Group F. Abinader, Ed. Internet-Draft Instituto Nokia de Tecnologia Intended status: Standards Track S. Gundavelli, Ed. Expires: July 5, 2012 K. Leung Cisco S. Krishnan Ericsson D. Premec Unaffiliated January 2, 2012 Bulk Binding Update Support for Proxy Mobile IPv6 draft-ietf-netext-bulk-re-registration-09 Abstract For extending the lifetime of a mobility session, the Proxy Mobile IPv6 specification requires the mobile access gateway to send a Proxy Binding Update message to the local mobility anchor on a per-session basis. In the absence of signaling semantics for performing operations with group specific scope, it results in significant amount of signaling traffic on a periodic basis between a given mobile access gateway and a local mobility anchor. This document defines an optimization to the binding update and revocation operations in Proxy Mobile IPv6 for performing operations with group specific scope with the use of a group identifier. Status of this Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on July 5, 2012. Copyright Notice Copyright (c) 2012 IETF Trust and the persons identified as the Abinader, et al. Expires July 5, 2012 [Page 1] Internet-Draft Bulk Binding Update Support January 2012 document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Conventions & Terminology . . . . . . . . . . . . . . . . . . 4 2.1. Conventions . . . . . . . . . . . . . . . . . . . . . . . 4 2.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4 3. Bulk Binding Update Overview . . . . . . . . . . . . . . . . . 4 3.1. Motivation . . . . . . . . . . . . . . . . . . . . . . . . 4 3.2. General Operation . . . . . . . . . . . . . . . . . . . . 5 4. Message formats . . . . . . . . . . . . . . . . . . . . . . . 7 4.1. Extensions to Proxy Binding Update Message . . . . . . . . 8 4.2. Extensions to Proxy Binding Acknowledgment Message . . . . 9 4.3. Mobile Node Group Identifier Option . . . . . . . . . . . 9 4.4. Status Codes . . . . . . . . . . . . . . . . . . . . . . . 10 5. Protocol Considerations . . . . . . . . . . . . . . . . . . . 11 5.1. MAG Considerations . . . . . . . . . . . . . . . . . . . . 11 5.1.1. Enabling Bulk Binding Operation Support for a Mobility Session . . . . . . . . . . . . . . . . . . . 11 5.1.2. Supporting Bulk Binding Updates . . . . . . . . . . . 13 5.2. LMA Considerations . . . . . . . . . . . . . . . . . . . . 14 5.2.1. Enabling Bulk Binding Operation Support for a Mobility Session . . . . . . . . . . . . . . . . . . . 14 5.2.2. Supporting Bulk Binding Updates . . . . . . . . . . . 16 6. Protocol Configuration Variables . . . . . . . . . . . . . . . 18 6.1. Local Mobility Anchor - Configuration Variables . . . . . 18 6.2. Mobile Access Gateway - Configuration Variables . . . . . 18 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19 8. Security Considerations . . . . . . . . . . . . . . . . . . . 20 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 20 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 20 10.1. Normative References . . . . . . . . . . . . . . . . . . . 20 10.2. Informative References . . . . . . . . . . . . . . . . . . 20 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 21 Abinader, et al. Expires July 5, 2012 [Page 2] Internet-Draft Bulk Binding Update Support January 2012 1. Introduction The Proxy Mobile IPv6 base specification [RFC5213] requires the Mobile Node Identifier option to be present in the mobility signaling messages, such as in the Proxy Binding Update and Proxy Binding Acknowledgement messages. It essentially limits the operational scope of the signaling messages to a single mobility session. These signaling messages lack the capability to identify a group of mobility sessions which have a common characteristic so as to perform operations on the entire group. There is a need to have semantics for defining a group affiliation for a mobility session, in order to allow relevant protocol operations to be performed on the entire group. The use of a group identifier in protocol operations can extend the scope of the operation to the entire group. The group identifier therefore provides a more optimal mechanism for protocol operations which would otherwise require multiple atomic transactions on a per mobile node basis. Following are some of the use-cases where the group identifier can be used. o For extending the lifetime of all the mobility sessions that are part of a group, the mobile access gateway can potentially send a single Proxy Binding Update message to the local mobility anchor, by including a group identifier that identifies all the mobility sessions that are part of that group. The local mobility anchor upon accepting the request can update the lifetime of all the mobility sessions that are part of that group. o In a blade architecture system running the local mobility anchor service, all the mobile node sessions anchored on a given card can belong to a single group. When a failure occurs on a specific card, the local mobility anchor can initiate the revocation signaling to the mobile access gateway by sending a single revocation request carrying the group identifier. o The mobile access gateway, or the local mobility anchor can choose to revoke all the mobility sessions belonging to a specific group. In such cases the mobile access gateway or the local mobility anchor can perform the binding revocation signaling using the group identifier associated with a specific set of mobile nodes. This document defines a new mobility option, Mobile Node Group Identifier option, which can be used in binding update and binding revocation related operations, for performing operations with group specific scope. Abinader, et al. Expires July 5, 2012 [Page 3] Internet-Draft Bulk Binding Update Support January 2012 2. Conventions & Terminology 2.1. Conventions The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119]. 2.2. Terminology All the mobility related terms used in this document are to be interpreted as defined in the base Proxy Mobile IPv6 specifications [RFC5213] and [RFC5844]. Additionally, this document uses the following abbreviations: Bulk Binding Update A binding update operation that has group specific scope. A binding operation is associated with a specific mobility session. However, a Bulk binding update operation is associated with multiple mobility sessions. This operation is not relevant for new mobility session(s) creations. Bulk Binding Update Group A group of mobility sessions that are part of the same logical group and therefore share a common group identifier. This group is the bulk binding update group. The mobility entities can perform binding update related operations such as lifetime extension and revocation operations on this entire group, identified by bulk binding update group identifier. 3. Bulk Binding Update Overview 3.1. Motivation In a typical Proxy Mobile IPv6 domain, a local mobility anchor serves multiple mobile access gateways and the capacity of that node with respect to the number of mobility sessions that it can host is quite high, typically in the order of few millions. As the number of mobility sessions hosted by a local mobility anchor goes up, so is the amount of signaling traffic related to periodic binding update related traffic. The currently specified approach of binding update procedure for extending the lifetime, where the mobile access gateway is required to send a unique binding update message for each mobility session, Abinader, et al. Expires July 5, 2012 [Page 4] Internet-Draft Bulk Binding Update Support January 2012 even when there is no change to the session state is inefficient or sub-optimal. These periodic binding update messages consume significant amount of network resources, both in terms of processing power and in terms of network bandwidth and at both the peers. There is an opportunity to optimize the signaling procedures by allowing the local mobility anchor and the mobile access gateway to perform bulk binding update operations. This document specifies extensions to Proxy Mobile IPv6 signaling for performing binding update and revocation operations on a group on mobility sessions. These extensions do not take away the existing functionality of performing binding operations on a single mobility session. 3.2. General Operation The bulk binding update mechanism specified in this document allows the mobile access gateway and the local mobility anchor to perform binding update and revocation operations on a group of mobility sessions. As part of the initial signaling during mobility session establishment, the local mobility anchor and the mobile access gateway exchange the respective bulk binding update group identifiers for that mobility session. Subsequently both the peers can perform bulk operations on those groups by presenting the bulk binding update group identifier in the signaling messages. A mobile access gateway when sending a Proxy Binding Update message after detecting a new mobile node on its access link, can request the local mobility anchor to assign a bulk binding update group identifier for the mobile node's mobility session. This is indicated by setting the (B) flag in the Proxy Binding Update to a value of (1). The mobile access gateway will also assign a bulk binding update group identifier (or it may assign a default bulk binding update group - ALL-Sessions) and include that in the Mobile Node Group Identifier option. The local mobility anchor upon accepting the request will group the mobility session to a specific bulk binding update group (or it may assign it to the default bulk binding update group - ALL-Sessions) and return this bulk binding update group identifier in Proxy Binding Acknowledgement message. It will also set the (B) flag in the Proxy Binding Acknowledgement message to a value of (1). The bulk binding update group identifier is carried in the Mobile Node Group Identifier option, described in Section 4.3. Once the bulk binding update group identifiers are exchanged, the local mobility anchor and the mobile access gateway can perform binding operations on those entire groups, by including the bulk binding update group identifier in the signaling messages. For example, the mobile access gateway can extend the lifetime of all the Abinader, et al. Expires July 5, 2012 [Page 5] Internet-Draft Bulk Binding Update Support January 2012 mobility sessions that are part of a group by sending a single Proxy Binding Update message with that bulk binding update group identifier. Similarly, the local mobility anchor can revoke all the mobility sessions that are part of a group, by including that group identifier in the Proxy Binding Revocation message. Figure 1 explains the operational sequence of the bulk binding update and revocation operations on a group of mobile nodes, MN1, MN2 and MN3. MAG LMA (1) | | MN1-------| (2) PBU | |--------------------------->| | * (3) | (4) PBA | |<---------------------------| * (5) | (6) | | MN2-------| | * (7)........................| (8) | | MN3-------| | * (9)........................| | | | (10) PBU | |--------------------------->| | * (11) | (12) PBA | |<---------------------------| * (13) | | | (14) BRI | |<---------------------------| | * (15) | (16) BRA | |--------------------------->| * (17) | | | Figure 1: Exchange of Group Identifier o (1) to (2): MAG detects the mobile node's (MN1) attachment to the access link. The MAG groups the mobile node to a specific bulk binding update group, (M1). The MAG notifies this group identifier to the LMA by including it in the Mobile Node Group Abinader, et al. Expires July 5, 2012 [Page 6] Internet-Draft Bulk Binding Update Support January 2012 Identifier option of the PBU message. o (3): The LMA upon accepting the PBU, creates a mobility session and groups the mobility session to a specific bulk binding update group, (L1). The LMA updates the mobile node's BCE entry to include the bulk binding update group identifier, (L1) and the bulk binding update group identifier presented by the MAG, (M1). The LMA also notifies the MAG about the bulk binding update group identifier (L1), by including it in the PBA. o (4) to (5): The MAG upon receiving the PBA updates the BUL entry for that mobility session to include the bulk binding update group identifiers (L1) and (M1). At this point, both the LMA and MAG are aware of the mobile node's bulk binding update group identifiers assigned by the peers. o (6) to (9): The above steps (1 through 5) are repeated here for MN2 and MN3, details are omitted. At the end of step (9), the MAG completes the signaling with the LMA. The MAG assigns the mobile nodes, MN2 and MN3 to bulk binding update groups, M1 and M2 respectively, while the LMA assigns them both to the same to the bulk binding update group, (L1). o At this point, LMA has assigned MN1, MN2 and MN3 to the bulk binding update group of (L1), while the MAG has assigned MN1 and MN2 to the group (M1) and MN3 to group (M2). Both the peers can now perform binding operations on a group of mobility sessions identified by the respective bulk binding update group identifier. o (10) to (13): The MAG sends a periodic binding update message for extending the lifetime of all the mobility sessions that are part of the bulk binding update group, (M1). It includes the bulk binding update group identifier, (M1) in the PBU. The LMA upon accepting the PBU, extends the lifetime of both MN1 and MN2, which are part of the group (M1). o (14) to (16): The LMA decides to revoke all the sessions that are part of bulk binding update group, L1. The LMA sends a BRI message with the bulk binding update group identifier, (L1). The MAG upon accepting the BRI message revokes all the MN1, MN2 and MN3 mobility sessions, which are part of that bulk binding update group, (L1). 4. Message formats This section identifies the extensions to Proxy Mobile IPv6 signaling messages that are required for supporting this specification. Abinader, et al. Expires July 5, 2012 [Page 7] Internet-Draft Bulk Binding Update Support January 2012 4.1. Extensions to Proxy Binding Update Message 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sequence # | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |A|H|L|K|M|R|P|F|T|B| Reserved | Lifetime | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | . . . Mobility options . . . | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 2 A new flag, Bulk-Binding-Update (B) flag is defined in the Proxy Binding Update message specified in [RFC5213]. The bit-value of Bulk-Binding-Update (B) flag in the flags field of the message will be (IANA-1). If the Bulk-Binding-Update flag (B) is set to a value of (1), it informs the local mobility anchor to assign the mobile node's mobility session to the bulk binding operation group. If the (B) flag is set to a value of (0), the local mobility anchor MUST exclude the mobile node's mobility session from the bulk binding operation group and thus any any binding update, or binding revocation operations with bulk scope will not be applied to that mobility session. This flag MUST be set to value of (0), when the (P) flag is set to a value of (0). All other fields in the Proxy Binding Update message and the mobility options that can be carried in the message confirm to the respective specifications. Abinader, et al. Expires July 5, 2012 [Page 8] Internet-Draft Bulk Binding Update Support January 2012 4.2. Extensions to Proxy Binding Acknowledgment Message 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Status |K|R|P|T|B| Res.| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sequence # | Lifetime | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | . . . Mobility options . . . | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 3: Proxy Binding Acknowledgment Message A new flag, Bulk-Binding-Update (B) flag is defined in the Proxy Binding Acknowledgment message specified in [RFC5213]. The bit-value of Bulk-Binding-Update (B) flag in the flags field of the message is (IANA-2). If the Bulk-Binding-Update flag (B) is set to a value of (1), it serves as an indication to the mobile access gateway that the mobile node's mobility session was successfully added to the bulk binding operation group. The value of the flag MUST be set to the value of (0), if the value of the (B) flag in the Proxy Binding Update message that it received from the mobile access gateway was set to a value of (0). This flag MUST be set to value of (0), when the (P) flag is set to a value of (0). All other fields in the Proxy Binding Acknowledgment message and the mobility options that can be carried in the message conform to the respective specifications. 4.3. Mobile Node Group Identifier Option A new option, Mobile Node Group Identifier option is defined for using it in Proxy Mobile IPv6 signaling messages exchanged between a local mobility anchor and a mobile access gateway. This option is used for carrying the mobile node's group identifier. There can be multiple instances of this option in a given signaling message, however, each of the instance SHOULD have a different sub-type value. This option is a generic option and this specification uses only the sub-type value of (1). The alignment requirement for this option is 4n. Abinader, et al. Expires July 5, 2012 [Page 9] Internet-Draft Bulk Binding Update Support January 2012 The type value for this option is (IANA-3). 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | Sub-type | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Mobile Node Group Identifier | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 4: Mobile Node Group Identifier Option Type <(IANA-3)> Length 8-bit unsigned integer indicating the length in octets of the option, excluding the type and length fields. The value for this field MUST be set to a value of (6). Sub-type Identifies the specific group type. This number space will be managed by the IANA. The sub-type value of (1) is reserved for Bulk Binding Update Group. Mobile Node Group Identifier A 32-bit field containing the mobile node's group identifier. The value of (0) is reserved and SHOULD NOT be used. The value of (1), ALL-SESSIONS is the default group of all mobility sessions established between a given local mobility anchor and mobile access gateway. The group identifier reflects the group affiliation of a mobile node. 4.4. Status Codes This document defines the following new Status codes values for use in the Proxy Binding Acknowledgement message. These values are to be allocated from the same numbering space, as defined in Section 6.1.8 of [RFC6275]. INVALID_MOBILE_NODE_GROUP_IDENTIFIER: (IANA-5) Invalid group identifier value in the request Abinader, et al. Expires July 5, 2012 [Page 10] Internet-Draft Bulk Binding Update Support January 2012 5. Protocol Considerations 5.1. MAG Considerations The following considerations MUST be applied by the mobile access gateway when supporting this specification. The conceptual Binding Update List entry data structure maintained by the mobile access gateway, described in Section 6.1 of [RFC5213], MUST be extended to include the mobile node's bulk binding update group identifiers, LMA-Bulk-Binding-Update-Group-Id and MAG-Bulk- Binding-Update-Group-Id. The LMA-Bulk-Binding-Update-Group-Id is the bulk binding update group identifier of that mobility session at the local mobility anchor, and which is received in the Mobile Node Group Identifier option of the Proxy Binding Acknowledgement message. The MAG-Bulk-Binding-Update-Group-Id is the bulk binding update group identifier assigned locally by the mobile access gateway for that mobility session. The mobile access gateway SHOULD maintain a global list, which identifies the list of bulk binding update group specific to each local mobility anchor. Example: LMA-1(G1, G2) LMA-2(G3, G2). 5.1.1. Enabling Bulk Binding Operation Support for a Mobility Session The following section identifies the considerations for the mobile access gateway for exchanging the mobile node's group identifiers in the Proxy Binding Update and Proxy Binding Acknowledgement messages. It should be noted that these considerations are relevant only during the establishment of a specific mobility session and are not relevant when initiating bulk binding updates on a group of mobility sessions. o When sending a Proxy Binding Update message to the local mobility anchor, the mobile access gateway MAY choose to request the local mobility anchor to enable bulk binding update support for the mobility session associated with that Proxy Binding Update request. When making such request, the Bulk-Binding-Update flag (B) in the request MUST be set to a value of (1) and the Mobile Node Identifier [RFC4283] option MUST be present. The decision to request the bulk binding update support for a mobile node is a matter of local policy at the mobile access gateway and is controlled by the configuration variable, RequestBulkBindingUpdateSupportForMobilitySession. o The mobile access gateway SHOULD also assign a bulk binding update group identifier for the mobile node based on its own grouping considerations. When such grouping is done, the mobile access gateway SHOULD send the assigned group identifier by including Abinader, et al. Expires July 5, 2012 [Page 11] Internet-Draft Bulk Binding Update Support January 2012 this identifier in the Mobile Node Group Identifier option of the Proxy Binding Update message. If there is no such grouping is done, the mobile access gateway SHOULD include the default group identifier value of (ALL-SESSIONS) in the Mobile Node Group Identifier option. o When sending the Mobile Node Group Identifier option in the binding update messages related to the individual session establishment, the Bulk-Binding-Update (B) flag in the request MUST be set to a value of (1). However, when initiating any binding update operations with group specific scope, the Bulk- Binding-Update (B) flag in the request MUST always be set to a value of (0), with the Mobile Node Group Identifier option present in the request. o If the received Proxy Binding Acknowledgment message has the Bulk- Binding-Update flag (B) in the reply set to a value of (0), this is in response to a Proxy Binding Update request with the Bulk- Binding-Update flag (B) set to a value of (1), it is an indication that the local mobility anchor has denied the request for supporting bulk binding update operations for that mobility session and that the mobility session is not associated with any bulk binding operation group. The mobile access gateway SHOULD set the bulk binding update group identifier values, LMA-Bulk- Binding-Update-Group-Id and MAG-Bulk-Binding-Update-Group-Id values to (0). Furthermore, the mobility session should be excluded from any bulk binding update operations. o If the received Proxy Binding Acknowledgment message has the status code value set to (0) (Proxy Binding Update accepted), the Bulk-Binding-Update flag (B) in the reply is set to a value of (1), it is an indication that the local mobility anchor has accepted the request to allow bulk binding updates on that mobility session. Furthermore, the Mobile Node Group Identifier option in the reply contains the bulk binding update group identifier for that mobility session assigned by the local mobility anchor. The mobile access gateway SHOULD update the LMA- Bulk-Binding-Update-Group-Id in the Binding Update List entry with the Identifier present in the received option. However, if the received Proxy Binding Acknowledgement message has the Bulk- Binding-Update flag (B) set to a value of (1), but if the Mobile Node Group Identifier option is not present, the message MUST be considered as malformed and ignored. o At any point of time, the mobile access gateway chooses to request the local mobility anchor to disable bulk binding update support for a mobility session, it MUST send a Proxy Binding Update message with the (B) flag set to a value of (0) and by including Abinader, et al. Expires July 5, 2012 [Page 12] Internet-Draft Bulk Binding Update Support January 2012 the Mobile Node Identifier [RFC4283] option. This message is sent as a normal binding update request for lifetime extension. Considerations from section 6.9.1 [RFC5213] MUST be applied. 5.1.2. Supporting Bulk Binding Updates The following section identifies the considerations for mobile access gateway for performing binding update and revocation operations with group specific scope. o For extending the lifetime of all mobility sessions that share the same bulk binding update group identifier, the mobile access gateway MAY choose to send a Bulk binding update request. For making such request, it can send a Proxy Binding Update message to the local mobility anchor, including the Mobile Node Group Identifier option with sub-type value of (1) (bulk binding update group), and with the Bulk-Binding-Update flag (B) set to a value of (0). The identifier value in the option MUST be set to the bulk binding update group identifier of the group for which bulk binding update operation is being requested. The message MUST NOT include any individual session identifiers such as, Mobile Node Identifier option [RFC5213], Home Network Prefix option [RFC5213], the IPv4 Home Address Request option [RFC5844], or the GRE Key option [RFC5845]. All the Considerations from section 5.3.3 [RFC5213] MUST be followed when sending this request, with exception related to the use of Mobile Node Group Identifier option in place of the individual session identifiers. o When requesting binding revocation for all the sessions that share the same bulk binding update group identifier, the mobile access gateway MAY choose to send a Bulk revocation request. For making such request, it can send a Binding Revocation Indication message to the local mobility anchor, including the Mobile Node Group Identifier option, with sub-type value of (1) (bulk binding update group). The identifier value in the option MUST be set to the bulk binding update group identifier of the group for which bulk binding update operation is being requested. The message MUST NOT include any individual session identifiers such as, Mobile Node Identifier option [RFC5213], Home Network Prefix option [RFC5213], the IPv4 Home Address Request option [RFC5844] or the GRE Key option [RFC5845]. All the Considerations from section 9.2 [RFC5846] MUST be followed when sending this request, with exception related to the use of Mobile Node Group Identifier option in place of the individual session identifiers. o Any time the mobile access gateway receives a Binding Revocation Indication Message [RFC5846], with a Mobile Node Group Identifier option present in the request and with sub-type value of (1) (bulk Abinader, et al. Expires July 5, 2012 [Page 13] Internet-Draft Bulk Binding Update Support January 2012 binding update group), the mobile access gateway MUST consider the request as a bulk revocation request, with the request scope for revoking of all the mobility sessions that share the same bulk binding update group identifier (present in the Mobile Node Group Identifier option). However, if the received request also includes a Mobile Node Identifier option [RFC5213], Home Network Prefix option [RFC5213], the IPv4 Home Address Request option [RFC5844], or the GRE Key Option [RFC5845], the mobile access gateway MUST consider this as an invalid message; it MUST reject the Binding Revocation Indication message and send a Binding Revocation Acknowledgement message with the Status field set to a value of 128 (Binding Does NOT Exist). All the considerations from [RFC5846] apply when processing binding revocation request, except making the scope of the operation apply to a set of mobility sessions identified by the bulk binding update group identifier present in the request. 5.2. LMA Considerations For supporting this specification, the following considerations MUST be applied by the local mobility anchor when processing Proxy Mobile IPv6 signaling messages. The conceptual Binding Cache entry data structure maintained by the local mobility anchor, described in Section 6.1 of [RFC5213], MUST be extended to include the mobile node's bulk binding update group identifiers, LMA-Bulk-Binding-Update-Group-Id and MAG-Bulk-Binding- Update-Group-Id. These are 32-bit unsigned integer values. The MAG- Bulk-Binding-Update-Group-Id reflects the bulk binding update group identifier assigned by the mobile access gateway and which is received in the Proxy Binding Update message. The LMA-Bulk-Binding- Update-Group-Id is the bulk binding update group identifier assigned locally by the local mobility anchor. 5.2.1. Enabling Bulk Binding Operation Support for a Mobility Session This section identifies the considerations for local mobility anchor for assigning a bulk binding update group identifier to a mobility session. o The local mobility anchor will process a received Proxy Binding Update message as specified in [RFC5213]. However, if the (B) flag in the received Proxy Binding Update message is set to a value of (1) and if it includes a Mobile Node Group Identifier option with sub-type value of (1) (bulk binding update group), the local mobility anchor MUST apply the following additional considerations. Abinader, et al. Expires July 5, 2012 [Page 14] Internet-Draft Bulk Binding Update Support January 2012 o If the (B) flag in the received Proxy Binding Update message is set to a value of (1) and with the Mobile Node Group Identifier option is present in the request, the message serves as a request to the local mobility anchor to include the mobile node's session to the bulk binding update group. o Upon successful processing and acceptance of the Proxy Binding Update, the local mobility anchor MAY choose to enable bulk binding update support for this mobility session. The decision whether to enable bulk binding update support for that mobility session is a matter of local policy and is controlled by the configuration variable, AcceptBulkBindingUpdateReqMobilitySession. o For enabling the bulk binding update support for the mobility session, the local mobility anchor SHOULD associate the mobility session to a specific bulk binding update group locally. The specific details on how the local mobility anchor associates the given mobility session to a specific bulk binding update group is outside the scope of this document. The local mobility anchor MAY choose to assign a default bulk binding update group identifier value of (ALL-SESSIONS), indicating that all the mobility sessions from that mobile access gateway are part of that group. The local mobility anchor SHOULD update the bulk binding update group identifier values in the Binding Cache entry, LMA-Bulk-Binding- Update-Group-Id and MAG-Bulk-Binding-Update-Group-Id to the respective values. o If the bulk binding update support is enabled for the mobile node's mobility session, the local mobility anchor MUST send the assigned bulk binding update group identifier as part of the Mobile Node Group Identifier option, with sub-type value of (1) (bulk binding update group) in the Proxy Binding Acknowledgment message that it sends to the mobile access gateway. The (B) flag in the Proxy Binding Acknowledgment message MUST be set to value of (1). o If the bulk binding update support is not enabled for the mobile node's mobility session, the local mobility anchor MUST NOT include the Mobile Node Group Identifier option with a sub-type value of (1) in the Proxy Binding Acknowledgment reply that it sends to the mobile access gateway. Furthermore, the (B) flag in the Proxy Binding Acknowledgment message MUST be set to value of (0). It is to be noted that the Mobile Node Group Identifier option is a generic option and new sub-types may be defined by future specifications. o If the received Proxy Binding Update message is not a bulk binding update request, (i.e., the (B) flag is set to a value of (0) and Abinader, et al. Expires July 5, 2012 [Page 15] Internet-Draft Bulk Binding Update Support January 2012 the Mobile Node Group Identifier option is not present), but is a request for extending the lifetime of an existing mobility session which is already part of a bulk binding update group, then the local mobility anchor MUST process the request as specified in [RFC5213]. However, the value of (0) in the (B) flag in the message serves as a request for the local mobility anchor to remove the session from performing bulk binding update operations. Upon accepting the request, the mobility session MUST be removed from the bulk binding update group. The local mobility anchor SHOULD set the bulk binding update group identifier values in the Binding Cache entry, LMA-Bulk-Binding-Update-Group-Id and MAG- Bulk-Binding-Update-Group-Id values to (0). o Any time the local mobility anchor detects that the mobile node has roamed and changed its point of attachment to a new mobile access gateway, it SHOULD also update the bulk binding update group identifier of the mobility session. Additionally, it should also update the existing group identifiers associated with that session. As part of sending the Proxy Binding Acknowledgment to the new mobile access gateway, it MUST include the updated group identifier in the Mobile Node Group identifier option. However, if the if the received Proxy Binding Update from the new mobile access gateway did not have the (B) flag set to a value of (1), then it MUST NOT include the mobility session in any of bulk binding update group and MUST NOT include the Mobile Node Group identifier option with the sub-type value of (1). o Any time a mobile node's mobility session is de-registered by the mobile access gateway, or the session is revoked for administrative or any other reasons, the mobility session MUST also be removed from the bulk binding update group. 5.2.2. Supporting Bulk Binding Updates The following section identifies the considerations for local mobility anchor for performing binding update and revocation operations with group specific scope. o Any time the local mobility anchor receives a Proxy Binding Update message with the (B) flag in the request is set to a value of (0) and if a Mobile Node Group Identifier option present in the request and with sub-type value of (1) (bulk binding update group), the local mobility anchor MUST consider the request as a bulk binding update request, with the request scope for extending the lifetime of all the mobility sessions that share the same group identifier present in the Mobile Node Group Identifier option. However, if the received request also includes any individual session identifiers such as, Mobile Node Identifier Abinader, et al. Expires July 5, 2012 [Page 16] Internet-Draft Bulk Binding Update Support January 2012 option [RFC5213], Home Network Prefix option [RFC5213], the IPv4 Home Address Request option [RFC5844], or the GRE Key option [RFC5845] the local mobility anchor MUST consider this as an invalid message; it MUST reject the Proxy Binding Update message and send a Proxy Binding Acknowledgement message with the Status field set to INVALID_MOBILE_NODE_GROUP_IDENTIFIER (Invalid group identifier value in the request). o The local mobility anchor MUST consider the message as a request for extending the lifetime of all the mobility sessions that are associated to each of group identifier from the Mobile Node Group Identifier option. There can be multiple instances of the Mobile Node Group Identifier option present in the request. However, the group identifier value in each of these options MUST be different. Currently, this specification only support sub-type value of (1) (bulk binding update group). If this requirement is not met, the local mobility anchor MUST reject the Proxy Binding Update message and send a Proxy Binding Acknowledgement message with the Status field set to INVALID_MOBILE_NODE_GROUP_IDENTIFIER (Invalid group identifier value in the request). o Upon accepting the bulk binding update request, the local mobility anchor SHOULD extend the lifetime for all the mobility sessions that are part of bulk binding update group identified by the group identifier in the Mobile Node Group Identifier in the message. Considerations from [RFC5213] MUST be applied for extending the lifetime of a mobile node's session. It MUST also send a Proxy Binding Acknowledgment message with the Status field value set to 0 (Proxy Binding Update accepted). The lifetime field in the message MUST be set to the allocated lifetime for all the mobility sessions. The message MUST also include the Mobile Node Group Identifier option, with the identifier value copied from the Mobile Node Group Identifier option present in the received Proxy Binding Update message. o If the local mobility anchor rejects the bulk binding update request for any administrative reason, then it MUST NOT update the lifetime in the binding cache entries of any of the mobile nodes identified by the group identifier. The local mobility anchor SHOULD send a Proxy Binding Acknowledgment indicating the reason for the rejection in the status code. o Any time the local mobility anchor receives a Binding Revocation Indication Message [RFC5846], with a Mobile Node Group Identifier option present in the request and with sub-type value of (1) (bulk binding update group), the local mobility anchor MUST consider the request as a bulk revocation request, with the request scope for revoking of all the mobility sessions that share the same group Abinader, et al. Expires July 5, 2012 [Page 17] Internet-Draft Bulk Binding Update Support January 2012 identifier present in the Mobile Node Group Identifier option. However, if the received request also includes a Mobile Node Identifier option [RFC5213], Home Network Prefix option [RFC5213], the IPv4 Home Address Request option [RFC5844], or the GRE Key Option [RFC5845], the local mobility anchor MUST consider this as an invalid message; it MUST reject the Binding Revocation Indication message and send a Binding Revocation Acknowledgement message with the Status field set to a value of 128 (Binding Does NOT Exist). All the considerations from [RFC5846] apply when processing binding revocation request, except making the scope of the operation apply to a set of mobility sessions identified by the group identifier present in the request. o Upon accepting the Binding Revocation Indication request and completing the operation, the local mobility anchor MUST send a Binding Revocation Acknowledgement message with the Status field set to a value of 0 (success). The message MUST include the Mobile Node Group Identifier option, with the identifier value copied from the Mobile Node Group Identifier option present in the received Binding Revocation Indication message. 6. Protocol Configuration Variables 6.1. Local Mobility Anchor - Configuration Variables The local mobility anchor MUST allow the following variables to be configured by the system management. The configured values for these protocol variables MUST survive server reboots and service restarts. AcceptBulkBindingUpdateReqMobilitySession This flag indicates whether or not the local mobility anchor should accept the request from the mobile access gateway to enable bulk binding update support for the mobility session. The default value for this flag is set to (1), indicating that it SHOULD accept the request from the mobile access gateway. If the value of the flag is set to (0), the local mobility anchor MUST deny the request. 6.2. Mobile Access Gateway - Configuration Variables The mobile access gateway MUST allow the following variables to be configured by the system management. The configured values for these protocol variables MUST survive server reboots and service restarts. RequestBulkBindingUpdateSupportForMobilitySession Abinader, et al. Expires July 5, 2012 [Page 18] Internet-Draft Bulk Binding Update Support January 2012 This flag indicates whether or not the mobile access gateway should request the local mobility anchor to enable bulk binding update support for the mobility session. The default value for this flag is set to (1), indicating that the the mobile access gateway MUST set the bulk binding update flag (B) in the Proxy Binding Update request to a value of (1). If the flag is set to a value of (0), the mobile access gateway MUST set the bulk binding update flag (B) in the Proxy Binding Update to a value of (0). 7. IANA Considerations This document requires the following five IANA actions. o Action-1: This specification defines a new flag (B) to the Proxy Binding Update message, specified in [RFC5213]. This flag is described in Section 4.1. The value of the flag (B) needs to be allocated from the Binding Update Flags registry. o Action-2: This specification defines a new flag (B) to the Proxy Binding Acknowledgment message, specified in [RFC5213]. This flag is described in Section 4.2. The value of the flag (B) needs to be allocated from the Binding Acknowledgment Flags registry. o Action-3: This specification defines a new Mobility Header option, the Mobile Node Group Identifier option. This option is described in Section 4.3. The Type value for this option needs to be assigned from the same numbering space as allocated for the other mobility options [RFC6275]. o Action-4: The Sub-type field of the Mobile Node Group Identifier option introduces a new number space. This number space needs to be managed by IANA, under the Registry, Mobile Node Group Identifier Type Registry. This specification reserves the sub- type value of (1) (Bulk Binding Update Group). Approval of new sub-type values are to be made through IANA Expert Review. o Action-5: This document also defines a new status value INVALID_MOBILE_NODE_GROUP_IDENTIFIER (Invalid group identifier value in the request: IANA-5) for use in Proxy Binding Acknowledgement message, as described in Section 4.4. This value is to be assigned from the same number space as allocated for other Status codes [RFC6275]. The allocated value has to be greater than 128. Abinader, et al. Expires July 5, 2012 [Page 19] Internet-Draft Bulk Binding Update Support January 2012 8. Security Considerations The Mobile Node Group Identifier option defined in this specification is for use in Proxy Binding Update and Proxy Binding Acknowledgement messages. This option is carried like any other mobility header option and it does not require any other special security considerations. The bulk binding update and the bulk revocation operations specified in this document, perform operations on a group of mobility sessions. If proper authorization checks are not in place, a malicious node may be able to hijack a mobile node's mobility session or may carry out a denial- of-service attack. To prevent this attack, this specification requires the local mobility anchor to allow only authorized mobile access gateways to perform bulk operations. 9. Acknowledgements The authors would like to specially thank Jouni Korhonen, Basavaraj Patil Carlos Jesus Bernardos Cano and Jari Arkko for their reviews and inputs to this document. 10. References 10.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC5213] Gundavelli, S., Leung, K., Devarapalli, V., Chowdhury, K., and B. Patil, "Proxy Mobile IPv6", RFC 5213, August 2008. [RFC5844] Wakikawa, R. and S. Gundavelli, "IPv4 Support for Proxy Mobile IPv6", RFC 5844, May 2010. [RFC5846] Muhanna, A., Khalil, M., Gundavelli, S., Chowdhury, K., and P. Yegani, "Binding Revocation for IPv6 Mobility", RFC 5846, June 2010. [RFC6275] Perkins, C., Johnson, D., and J. Arkko, "Mobility Support in IPv6", RFC 6275, July 2011. 10.2. Informative References [RFC4283] Patel, A., Leung, K., Khalil, M., Akhtar, H., and K. Chowdhury, "Mobile Node Identifier Option for Mobile IPv6 Abinader, et al. Expires July 5, 2012 [Page 20] Internet-Draft Bulk Binding Update Support January 2012 (MIPv6)", RFC 4283, November 2005. [RFC5845] Muhanna, A., Khalil, M., Gundavelli, S., and K. Leung, "Generic Routing Encapsulation (GRE) Key Option for Proxy Mobile IPv6", RFC 5845, June 2010. Authors' Addresses Fuad Abinader (editor) Instituto Nokia de Tecnologia Av. Torquato Tapajos, 7200 - Km. 12 - Col Terra Nova Manaus, AM 69048-660 BRAZIL Email: fuad.junior@indt.org.br Sri Gundavelli (editor) Cisco 170 West Tasman Drive San Jose, CA 95134 USA Phone: Fax: Email: sgundave@cisco.com URI: Kent Leung Cisco 170 West Tasman Drive San Jose, CA 95134 USA Phone: Fax: Email: kleung@cisco.com URI: Abinader, et al. Expires July 5, 2012 [Page 21] Internet-Draft Bulk Binding Update Support January 2012 Suresh Krishnan Ericsson 8400 Decarie Blvd. Town of Mount Royal, QC Canada Phone: +1 514 345 7900 x42871 Fax: Email: suresh.krishnan@ericsson.com URI: Domagoj Premec Unaffiliated Email: domagoj.premec@gmail.com Abinader, et al. Expires July 5, 2012 [Page 22]